Water Turbidity and Suspended Particulate Matter Concentration at Dredged Material Dumping Sites in the Southern Baltic

Abstract

Dredged material dumping is an activity that causes some of the greatest changes in coastal waters. It results in the need to regularly monitor the properties of seawater related to water quality. In this study, we present the first wide-ranging attempt to correlate seawater turbidity and suspended particulate matter (SPM) concentrations within dumping sites and adjacent waters on the basis of in situ measurements. In the years 2019–2020, we examined four dumping sites, namely Darłowo, Gdynia, Gdańsk, and DCT, located in Polish coastal waters of the Baltic Sea, in the course of four measurement campaigns conducted in the spring, summer, autumn, and winter. The measurements were conducted using a turbidity sensor to determine the turbidity, in formazin turbidity units (FTU), a spectrophotometer to determine the concentrations of nutrients (total phosphorus (P-tot), phosphate phosphorus (P-PO4−3), total nitrogen (N-tot), ammonium nitrogen (N-NH4+), and nitrate nitrogen (N-NO3−)), as well as glass microfiber filters to determine the concentrations of SPM. The analysis of the relationship between the turbidity and SPM within the dumping sites in comparison to reference points showed that the dumping sites are very complex waters and that the issue must be approached locally. The highest turbidity values were registered in the spring, and they correlated linearly with the SPM concentrations (R2 = 0.69). Moreover, we performed a statistical cluster analysis to illustrate the similarities between sampling points in the four dumpsites based on nutrient concentrations. We conclude that the influence of the dumping sites on the local bio-optical and chemical properties significantly exceeds their borders and spreads to the adjacent waters. Nutrient concentrations in many cases exceeded the legal policy limits.

The structure and diversity of denitrifying bacteria mediated by suspended particulate matter in aquaculture water bodies in Higher place pond

“…Ca 2+ ) with the particle surface [16,48,49,50]. However, the decrease of temperature and nutrients in winter limited the growth of archaea and the occulation of SPM to some extent [51,52]. The water samples in this study were collected in winter and the nutrient concentration was low, which led to the inability of archaea to occulate into larger particle sizes, so they only existed in small particle sizes.…”

Light Penetrating the Seawater Column as the Indicator of Oil Suspension—Monte Carlo Modelling for the Case of the Southern Baltic Sea

“…Failures of shelf mining equipment also happen [ 6 ]. The possible sources of oil presence in seawater, related to anthropogenic activities, can also be port canal-origin dredged material dumping [ 7 ] and oil installations [ 8 ].…”

The Potential of Multibeam Sonars as 3D Turbidity and SPM Monitoring Tool in the North Sea

“…This seasonal SPM signal is predominantly controlled by the biological cycle (phytoplankton blooms in spring and early summer) [10]. Furthermore, human activities such as the construction of offshore windmill parks [24] and dredging and dumping activities [25,26] are known to have farfield effects and may significantly increase SPM variability. Improving our understanding of both natural and human-induced SPM variability is therefore essential for sustainable coastal management.…”